Hostility, social support, and ambulatory cardiovascular activity.

The present study compared ambulatory blood pressure in male and female subjects preselected for high and low hostility levels and investigated interpersonal daily stress as a possible mediational mechanism. Ambulatory blood pressure and heart rate were measured in 48 male and female students previously classified as high or low on the Cook-Medley Hostility (Ho) Scale. Subjects wore an ambulatory monitor for a working day and also completed measures of perceived social support, daily interpersonal stress, and health behavior information. Results indicated that subjects scoring high on the Ho scale had higher mean levels of ambulatory systolic blood pressure than low Ho subjects, even when controlling for traditional risk factors, such as cigarette smoking. High Ho subjects also reported greater daily interpersonal stress and less social support than low Ho subjects. Perceived interpersonal stress partially accounted for the relationship between hostility and blood pressure. Subjects high in hostility showed greater mean ambulatory systolic blood pressure levels. Consistent with the transactional model of hostility and health, the relationship between hostility and blood pressure appears to be partially accounted for by the daily experience of interpersonal stress.